Headers Glowing HOT.
Race Director
Joined: Sep 2003
Posts: 16,838
Likes: 341
From: Database Error Indiana
Definitely get plugs for the AIR line on the exhaust manifolds. IT could be that outside air is being drawn into the exhaust and helping to create a lean condition.
You can get NPT pipe plugs at Home Depot or Lowes. I think they are 1/2" NPT. I did that on my 87 when I removed the AIR system. Just use a little anti-seize on the threads so the plugs can be removed if needed later.
You can get NPT pipe plugs at Home Depot or Lowes. I think they are 1/2" NPT. I did that on my 87 when I removed the AIR system. Just use a little anti-seize on the threads so the plugs can be removed if needed later.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Short novela of the Car and what I've done.
I am sure I got the TDC and distributor dead on accurate. I use a timing light to time the engine. It is during these timing sessions that I note the exhaust manifolds glowing extremely hot. They are glowing cherry red in 30 seconds or so.
I've confirmed the timing. I suspect tuning may be cause for running lean or rich. Don't know which. I've done a partial TPS and Idle speed adjustment. But because the manifolds get so hot I have not done any TPS adjustments.
Do I need to make any adjustment to the computer based off of:
New Fuel Injectors
No EGR
Throttle Body Bypass
I just wanted to let anyone trying to assist know the whole story rather then trying to drag it out of me little by little.
I am sure I got the TDC and distributor dead on accurate. I use a timing light to time the engine. It is during these timing sessions that I note the exhaust manifolds glowing extremely hot. They are glowing cherry red in 30 seconds or so.
I've confirmed the timing. I suspect tuning may be cause for running lean or rich. Don't know which. I've done a partial TPS and Idle speed adjustment. But because the manifolds get so hot I have not done any TPS adjustments.
Do I need to make any adjustment to the computer based off of:
New Fuel Injectors
No EGR
Throttle Body Bypass
I just wanted to let anyone trying to assist know the whole story rather then trying to drag it out of me little by little.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
You've just figured out part of your problem. You said the only time the headers glow red is when you are setting the timing. You have the esc disconnected and the timing at 6 degrees. The normal timing for a motor at idle is about 16-18 degrees. When you are at 6 degrees, you are over 10 degrees retarded. Unburnt fuel is burning in your manifolds. You may have other problems, but this one is a contributing factor.
It's important to know where the 6 degree BTDC mark is on the timing tab, and that the tab is even in the right place. I think there are a number of front covers that have tabs in slightly locations and the tabs are even different designs. The tab on my 87 uses v-shaped notches; each point and valley represents 2 degrees. Other SBC tabs use a rectangular shaped plate with lines.
And it is entirely possible that the outer ring of the balancer has slipped and the timing mark would then not be in the correct position. It might be reasonable to go back to basics and insure that #1 cylinder is at TDC and that the mark on the balancer is at the 0 degree mark on the timing tab.
Thread Starter
Advanced
Joined: Sep 2012
Posts: 79
Likes: 0
From: Fayetteville NC
Definitely get plugs for the AIR line on the exhaust manifolds. IT could be that outside air is being drawn into the exhaust and helping to create a lean condition.
You can get NPT pipe plugs at Home Depot or Lowes. I think they are 1/2" NPT. I did that on my 87 when I removed the AIR system. Just use a little anti-seize on the threads so the plugs can be removed if needed later.
You can get NPT pipe plugs at Home Depot or Lowes. I think they are 1/2" NPT. I did that on my 87 when I removed the AIR system. Just use a little anti-seize on the threads so the plugs can be removed if needed later.
I checked for every vacuum line I could figure out. This one still isn't connected. HVAC? It continues under to the center MAP vacuum connection.
This configuration on the Master cylinder can't be correct-
Finally- Here is the throttle body. I put a cap on the middle vacuum. I do not know what goes there. the lower one is where the radiator hose used to go.
I can still hear a slight hissing from the back of the throttle body. Near the distributor.
Fuel Pressure Regulator- Connected
EGR Valve- Connected
EGR Solenoid- Connected
Hidden vacuum line under Throttle body- Connected
I ran it at least a minute, then it started to get hot- in addition the radiator cap was off and water started spewing out like it was boiling over.
For all those telling me to check TDC again. I hear you. But dang it, I did 4 times.
I can get the piston stop to ensure that the ring hasn't slipped and to mark true TDC on the harmonic balancer.
Note: When you see the picture below, you may note the Fuel Pressure Gauge hooked up to the fuel rail. It is steady 45 lbs while running.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
that appears to be the coolant air bleed hose from behind egr tube.
forget checking TDC. if your engine starts, the timing is close enough. 6* is not retarded, and if it caused glowing exhaust they would all do it. we know for a fact that they do not.
you don't have the MAP connected?
throttle body close to distributor? is that a misprint? the brake booster tube/hose asm is back there.
forget checking TDC. if your engine starts, the timing is close enough. 6* is not retarded, and if it caused glowing exhaust they would all do it. we know for a fact that they do not.
you don't have the MAP connected?
throttle body close to distributor? is that a misprint? the brake booster tube/hose asm is back there.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
I don't think it's a big deal for you right now.
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Pro
Joined: Feb 2010
Posts: 677
Likes: 3
From: Metairie LA
When I was just getting mine to run, I capped off all vacuum ports except the FPR to troubleshoot. A vacuum leak could be anywhere along those old hard plastic lines or even under the dash (AC controls). Grab a pack of caps at any auto parts store.
Burning Brakes
Joined: Dec 2008
Posts: 1,021
Likes: 7
From: Morgan Hill and Marina California
I agree it can't be right. You gotta ask yourself where the two sides
of the loop are supposed to go, and is that other end open? That's the brake
booster. One side has to go to the intake plenum to supply vacuum.
On my '87 there's only one hose and it goes to the bottom of the intake
plenum just behind the #8 runner. On the bottom of the plenum it would
be real easy to miss plugging.
And get the power brakes working before you try to drive it, even
just to back it out of the garage.
Kudos for getting a basket case almost back together.
Chuck
of the loop are supposed to go, and is that other end open? That's the brake
booster. One side has to go to the intake plenum to supply vacuum.
On my '87 there's only one hose and it goes to the bottom of the intake
plenum just behind the #8 runner. On the bottom of the plenum it would
be real easy to miss plugging.
And get the power brakes working before you try to drive it, even
just to back it out of the garage.
Kudos for getting a basket case almost back together.
Chuck
Melting Slicks
Joined: Aug 2008
Posts: 2,082
Likes: 50
From: Palmdale CA
great advise...reduce the variables, and work the problems one at a time.
Thread Starter
Advanced
Joined: Sep 2012
Posts: 79
Likes: 0
From: Fayetteville NC
I agree it can't be right. You gotta ask yourself where the two sides
of the loop are supposed to go, and is that other end open? That's the brake
booster. One side has to go to the intake plenum to supply vacuum.
On my '87 there's only one hose and it goes to the bottom of the intake
plenum just behind the #8 runner. On the bottom of the plenum it would
be real easy to miss plugging.
And get the power brakes working before you try to drive it, even
just to back it out of the garage.
Kudos for getting a basket case almost back together.
Chuck
of the loop are supposed to go, and is that other end open? That's the brake
booster. One side has to go to the intake plenum to supply vacuum.
On my '87 there's only one hose and it goes to the bottom of the intake
plenum just behind the #8 runner. On the bottom of the plenum it would
be real easy to miss plugging.
And get the power brakes working before you try to drive it, even
just to back it out of the garage.
Kudos for getting a basket case almost back together.
Chuck
that appears to be the coolant air bleed hose from behind egr tube.
forget checking TDC. if your engine starts, the timing is close enough. 6* is not retarded, and if it caused glowing exhaust they would all do it. we know for a fact that they do not.
you don't have the MAP connected?
throttle body close to distributor? is that a misprint? the brake booster tube/hose asm is back there.
forget checking TDC. if your engine starts, the timing is close enough. 6* is not retarded, and if it caused glowing exhaust they would all do it. we know for a fact that they do not.
you don't have the MAP connected?
throttle body close to distributor? is that a misprint? the brake booster tube/hose asm is back there.
Just like C4cruiser states- maybe it goes back to the booster. I also assumed it could be the coolant line from the rear of the manifold. The one I have back there is in poor condition. But the bolt looks a lot smaller on the coolant line versus the mystery hose.
Speaking of that line, I've read you need to "burb" the coolant when you add it. Could this be the reason the coolant gets hot so quickly (under a minute).
That said- It looks like a fuel line to me.
Melting Slicks
Joined: Aug 2008
Posts: 2,082
Likes: 50
From: Palmdale CA
You mentioned in post #24 that you hear a hiss near the throttle body (distributor side) I'm thinking you may have a fair size Vacuum leak at the throttle body...it might not be a bad idea to remove and inspect the gasket and mating surface's. This could cause a lean condition as well..
Thread Starter
Advanced
Joined: Sep 2012
Posts: 79
Likes: 0
From: Fayetteville NC
I googled:
1990 corvette brake booster vacum lines
Went to images- and the first picture is the mystery hose.
Trying to find a good picture, or even better, a good picture with a write up.
1990 corvette brake booster vacum lines
Went to images- and the first picture is the mystery hose.
Trying to find a good picture, or even better, a good picture with a write up.
Thread Starter
Advanced
Joined: Sep 2012
Posts: 79
Likes: 0
From: Fayetteville NC
Breaking News!
Found it.
The Mystery hose bolts into the Rear of the plenum on the drivers side next to the last bolt to the runners.
I knew I heard a hissing noise.
I'll hook it up tomorrow and give everyone an update.
Found it.
The Mystery hose bolts into the Rear of the plenum on the drivers side next to the last bolt to the runners.
I knew I heard a hissing noise.
I'll hook it up tomorrow and give everyone an update.
Last edited by Rogman; Oct 29, 2012 at 02:13 AM.
Thread Starter
Advanced
Joined: Sep 2012
Posts: 79
Likes: 0
From: Fayetteville NC
That was it.
I'd like to Thank everyone for input! I'd be lost without it ( I still can't believe it was so obvious, laughing at me the whole time).
The shifter cable should be in tomorrow.
I need to figure out the coolant line coming from the intake manifold.
The oil pressure sensor is leaking.
The air filter doesn't quite fit right.
Change the oil.
Swap out the distributor I rebuilt but doesn't work, and has a broken bearing from me hammering it on.
-Rogman
I'd like to Thank everyone for input! I'd be lost without it ( I still can't believe it was so obvious, laughing at me the whole time).
The shifter cable should be in tomorrow.
I need to figure out the coolant line coming from the intake manifold.
The oil pressure sensor is leaking.
The air filter doesn't quite fit right.
Change the oil.
Swap out the distributor I rebuilt but doesn't work, and has a broken bearing from me hammering it on.
-Rogman
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
That hose that you figered out is the brake booster vac line. Get that on the booster the right way. Fairly important. That system thats in place now....not right.
Theres your massive air leak. No more red unless you see it in the mirror...
The coolant line from the rear of the intake baseplate is easy...its steel off the intake manifiold, then its hose to the heater hose that enters the heater core. IF the otriginal heater pipe assy is gone, (a dual pipe assy in front of the heater core) and you just have 2 hoses going in/out of the heater core, then you need to get a brass "T" in one of the heater hoses and run that 1/4" manifold line to that T. This dumps that hot egr water directly back into the system where it can aid the heater core and then go to the pump and radiator for cooling. The heater core tends to starve for hot water if there have been any changes in the cooling system (upgrades or different intake etc) because its easier for the hot water to go to the rad than it is to get thru the small heater core hoses. So that super hot 1/4 (or 3/8?) little line off the rear of the intake helps with that problem.
oh yeah...
congrats! solving a problem always feels good.
Wish finding problems felt as nice...I'd be a happy camper.
You;re halfway down the driveway now ! enjoy !
Theres your massive air leak. No more red unless you see it in the mirror...
The coolant line from the rear of the intake baseplate is easy...its steel off the intake manifiold, then its hose to the heater hose that enters the heater core. IF the otriginal heater pipe assy is gone, (a dual pipe assy in front of the heater core) and you just have 2 hoses going in/out of the heater core, then you need to get a brass "T" in one of the heater hoses and run that 1/4" manifold line to that T. This dumps that hot egr water directly back into the system where it can aid the heater core and then go to the pump and radiator for cooling. The heater core tends to starve for hot water if there have been any changes in the cooling system (upgrades or different intake etc) because its easier for the hot water to go to the rad than it is to get thru the small heater core hoses. So that super hot 1/4 (or 3/8?) little line off the rear of the intake helps with that problem.
oh yeah...
congrats! solving a problem always feels good.
Wish finding problems felt as nice...I'd be a happy camper.
You;re halfway down the driveway now ! enjoy !
Thread Starter
Advanced
Joined: Sep 2012
Posts: 79
Likes: 0
From: Fayetteville NC
That hose that you figered out is the brake booster vac line. Get that on the booster the right way. Fairly important. That system thats in place now....not right.
Theres your massive air leak. No more red unless you see it in the mirror...
The coolant line from the rear of the intake baseplate is easy...its steel off the intake manifiold, then its hose to the heater hose that enters the heater core. IF the otriginal heater pipe assy is gone, (a dual pipe assy in front of the heater core) and you just have 2 hoses going in/out of the heater core, then you need to get a brass "T" in one of the heater hoses and run that 1/4" manifold line to that T. This dumps that hot egr water directly back into the system where it can aid the heater core and then go to the pump and radiator for cooling. The heater core tends to starve for hot water if there have been any changes in the cooling system (upgrades or different intake etc) because its easier for the hot water to go to the rad than it is to get thru the small heater core hoses. So that super hot 1/4 (or 3/8?) little line off the rear of the intake helps with that problem.
oh yeah...
congrats! solving a problem always feels good.
Wish finding problems felt as nice...I'd be a happy camper.
You;re halfway down the driveway now ! enjoy !
Theres your massive air leak. No more red unless you see it in the mirror...
The coolant line from the rear of the intake baseplate is easy...its steel off the intake manifiold, then its hose to the heater hose that enters the heater core. IF the otriginal heater pipe assy is gone, (a dual pipe assy in front of the heater core) and you just have 2 hoses going in/out of the heater core, then you need to get a brass "T" in one of the heater hoses and run that 1/4" manifold line to that T. This dumps that hot egr water directly back into the system where it can aid the heater core and then go to the pump and radiator for cooling. The heater core tends to starve for hot water if there have been any changes in the cooling system (upgrades or different intake etc) because its easier for the hot water to go to the rad than it is to get thru the small heater core hoses. So that super hot 1/4 (or 3/8?) little line off the rear of the intake helps with that problem.
oh yeah...
congrats! solving a problem always feels good.
Wish finding problems felt as nice...I'd be a happy camper.
You;re halfway down the driveway now ! enjoy !
I was wondering which one to splice into. Hopefully the fain is gone tomorrow. I'll get it spliced in.
The connection at the manifold is loose. And the bolt looks chewed up. I hope it isn't stripped or worse.